Cladding of structural steelwork with fire protective material



Feb. 4, 1969 K. E. SIMMONS 3,425,558

CLADDING OF STRUCTURAL- STEELWORK WITH FIRE PROTECTIVE MATERIAL Sheet Filed Oct. 20, 1965 I'll !'.I 2

KENNETH ELfiSoN SIMMONS BY; V ATTORNEY W fl W 1 g 5 u T W, K fl/ a u 1 n 3 A h u i a K w T 2 a n: m F

K. E. SIMMONS OF STRUCTURAL STEELWORK WITH RE PROTECTIVE MATERIAL Sheet Feb" 4, 1969 CLADDING FI Flled Oct 20 1965 O R N EY United States Patent 1 Claim ABSTRACT OF THE DISCLOSURE Cladding for metal sectional members such as I-beams which can be easilyandl quickly attached to such members is achieved by the use of rigid blocks capable of interengagement with one another and with the sectional member. First blocks have a sectional form which is U-shaped and has an intermediate portion to abut the flange of the sectional member and two arm portions projecting therelfrom. Second blocks have a sectional form with an abutment portion to abut the web of the sectional member. Recessed parts in the sectional forms cooperate with pro jecting parts so as to inter-engage when said first blocks are set opposite said second blocks on a sectional member. The blocks are capable of relative lengthwise displacement relative to each other (at least during assembly) but prevented from transverse displacement. This cladding is especially useful for fire protection.

The invention relates to means for cladding structural steelwork with fire protective material.

An object of the invention is to provide a means for cladding a metal sectional member of a structure, said means being easily and quickly attached to said member by unskilled labour.

A further object of the invention is to provide such means in the form of sectional blocks which are of relatively simple shapes and which can easily be handled.

According to the invention there is provided means tfior cladding with fire protective material, a structural steelwork member (that is to say, a rolled steel section, a compound section or a plate girder) provided with at least one exposed flange, said means comprising a plurality of interlocking blocks formed wholly or mainly of said fire protective material, including at least one type of block capa ble of being placed in a position embracing a short sectron of said flange and at least one other type of block capable of being seated on said flange, or placed in abutment with it, in interlocking engagement with the first mentioned type of block whereby the latter is held against the structural steelwork member while embracing a short section of its flange, the first mentioned type of block being slidsble longitudinally on the structural steelwork member relative to said other type of block while maintaining its interlocked engagement therewith whereby, alternatively as desired, a plurality of said first type of block disposed end to end may each have their respective ends in line with the ends of respective blocks of said other type or may be staggered with relation to the ends of said individual blocks of said other type so that in the latter case the heat path from outside the interlocked blocks to at least part of the surface of the structural steelrwork member is tortuous.

In order that the invention may be fully understood and readily put into effect, embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which;

FIG. 1 is a cross section of a rolled steel joist clad with fire protective material,

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FIG. 2 is a side view thereof, on a somewhat reduced scale,

FIG. 3 is a scrap cross sectional view of a rolled steel joist being clad with fire protective material in an alternative manner, and

FIG. 4 is a cross sectional view of said joist after cladding has been completed, and

FIG. 5 is a semi-diagrammatic cross section of a rolled steel joist clad in a further alternative manner.

Referring now to FIG. 1 and FIG. 2 of the drawings, a rolled steel joist 10 is clad with fire protective material, in this instance a lightweight concrete, precast in the form of interlocking blocks or sections. Said interlocking blocks or sections comprise a series of lower blocks 11 each being so shaped as to embrace and clad a lower portion of a short length of the rolled steel joist, and a series of upper blocks 12 so shaped as to be placeable in position abutting against the faces of the web 13 of the joist to clad substantially the remainder of said short length of joist, said upper blocks then resting on the inner surfaces of the bottom flange 14 of said joist.

The lower blocks 11, which are substantially of U-shape, are Iformed with undercuts or grooves 15 and 16 for receiving raised lower edges 23 of the flanks of the upper blocks 12 so as to interlock therewith, and reinforcement rods 26 are cast in the lower blocks during their manufacture.

The interlocking sections are assembled in position on a rolled steel joist by holding one of the lower blocks in a position embracing the lower portion of a section of said joist, and sliding a pair of upper blocks, at opposite sides of the web of the joist, into interlocking engagement with said lower block from one end of the latter. A plurality of the upper blocks are assembled thus so as tobe disposed end to end along the length of the joist, and a plurality of lower blocks are also of course disposed in end to end relation in interlocking engagement with said upper blocks. When all but a short length of a joist has been clad, however, a pair of upper blocks cannot be inserted between the end [face 18 of the last lower block and the vertical face of a wall, for example. The upper blocks in interlocking engagement with the next adjacent lower block are, therefore, partially withdrawn therefrom and moved into interlocking engagement with said last lower block over approximately half the length thereof as shown in FIG. 2, and the spaces at both sides of the last-mentioned upper blocks are filled with grout. The whole can then be given a covering of plaster or other suitable material if required.

In the alternative arrangement illustrated in FIG. 3 and FIG. 4, a series of lower blocks 27 are formed in a similar manner to the blocks 11; being substantially of U-shape so as to embrace and clad a lower portion of a short length of a rolled steel joist 28. In this case, however, one of the legs 29 of each block 247 is longer than the other leg 30 and the minimum distance between the legs of the U is less than the width of the lower flange 31 of the joist so that, as shown in FIG. 3, said blocks can be manipulated into position as shown in full lines and then temporarily retained in position upon the lower flange 31 of the joist as shown in chain-dotted lines until upper blocks 32 and 33, correspondingly different in size according to which side of the joist they are to be fixed, are brought into position to interlock with said lower blocks.

In both the arrangements so far described, the upper surfa'ces of the joists are not clad by the upper blocks since the upper surface of horizontal structural steel members are usually load-bearing surfaces.

However, there is illustrated in FIG. 5 a further alternative arrangement of interlocking blocks or sections of fire protective material which, although primarily designed for the cladding of vertical structural steel members, could be employed for horizontal members which required to be totally clad.

In the further alternative arrangement, a pair of substantially U-shaped outer blocks 19 are so formed as to completely embrace a short length of a rolled steel joist 24 when placed in position thereon, abutting one against the other. A pair of inner blocks 25 are provided to retain said outer blocks in position, and are assembled in interlocking relation therewith by being moved axially of the joist, respectively in contact with opposite sides of the web of said joist, in order that respective raised edges or flanges 21 of the inner blocks may be received in respective undercuts or grooves 22 formed in the outer blocks.

In being built up with one interlocking set upon another (that is to say in end to end relation) the topmost pair of outer blocks may be retained in position by grout poured therewithin if insufiicient space remains above said topmost pair of outer blocks for a pair of inner blocks to be inserted.

Thus there is provided a means of cladding a metal sectional member of a structure, which means can be easily and quickly attached to said member by unskilled labour. A structure can therefore be clad more economically than hitherto. Furthermore, by virtue of the fact that the blocks are of relatively simple shapes they are economical to manufacture and they can be handled easily. It will be seen that alternatively, as desired, a plurality of a first type of block disposed end to end may each have their respective ends in line with the ends of respective blocks of another type of block or may be staggered with relation to the ends of individual blocks of said other type so that in the latter case the heat path from outside the interlocking blocks to at least part of the surface of the structural steel member on which they are assembled is tortuous.

Various modifications may be made Without departing from the scope of the invention. For example, at least some portions of the blocks may be cored out to save material and to result in blocks of minimum weight. Furthermore, contact surfaces of the blocks could if desired be buttered with grout during the cladding operation, or alternatively the blocks could be manufactured with chamfered edges to form open joints ready for pointing after cladding has been completed.

It will, of course, be understood that while the invention has been described, by way of example, as applied to a rolled steel joist (and of course structural steel members are usually of that form), the invention can quite Well be applied to means for cladding structural steelwork of any form provided with at least one flange.

What I claim is:

1. Cladding means for a sectional member of a structure having a web and at least one flange at right angles to said web, the cladding means comprising: a plurality of rigid first blocks of a first sectional form and a plurality of rigid second blocks of a second sectional form different from said first sectional form, said rigid blocks being interengageable with one another and with the sectional member and the ends of the first blocks being staggered in relation to the ends of the second blocks; said first sectional form being U-shaped and having an intermediate portion to abut said flange and a pair of spaced arm portions to be located on opposite sides of said web and extending from said intermediate portion, a projecting part and a recessed part on at least one of said arm portions, said projecting part being directed towards the other arm portion so that the minimum distance between said arm portions is along a line spaced from said intermediate portion; said second sectional form having an abutment portion to abut said web and a locating portion having a recessed part and a projecting part respectively being of complementary profile to and inter-engaging with the projecting part and the recessed part of said first sectional form to permit relative longitudinal displacement between said first and second blocks and to prevent transverse displacement of the blocks relative to each other and relative to said sectional member.

References Cited UNITED STATES PATENTS 675,867 6/1901 Austin 164110 1,389,785 9/1921 Riblet 249-90 1,567,245 12/1925 Collier et a1. 249-23 1,787,447 1/1931 Heeren 52-723 FOREIGN PATENTS 785,631 5/1935 France. 553,655 5/1943 Great Britain.

J. SPENCER OVERHOLSER, Primary Examiner.

V. RISING, Assistant Examiner.

US. Cl. X.R. 

